Using the LM1496 integrated circuit can be made a very simple frequency doubler
LM1496 can process only signals that do not exceed 25 mV: above this level, significant distortions occur, so that the scheme is provided with an input voltage divider. Thus it is possible to obtain, from an input signal of 500 mV, a signal of only 25 mV, at the LM1496's input.
To get to output a signal large enough, IC1's output signal is amplified by IC2 (operational amplifier), which is connected as a noninverting amplifier. Since the output of IC1 contains a DC component about 8 V, the coupling between the two stages will be via a capacitor C4.
For values of R15 and R16 IC2 data scheme achieves a gain equal to 16 (24 dB). General amplification of circuit depends on the input signal: if the input is 1.2 V gain is unitary, when input drops to 0.1 V, the increase will be only 0.1.